1. Field of the Invention
The present invention relates to a plasma processing device and a plasma processing method used for thermal plasma processing which processes a substrate by irradiating the substrate with thermal plasma, a low-temperature plasma processing which processes the substrate by irradiating the substrate with plasma by a reactive gas or with plasma and a reactive gas flow at the same time and other processing.
2. Description of Related Art
A semiconductor thin film such as polycrystalline silicon (poly-Si) is widely used for a thin-film transistor (TFT) and a solar cell in related art. As a method of forming the semiconductor thin film inexpensively, there is a method of irradiating an amorphous silicon film with laser light to crystallize the film. The laser process can be also applied to activation of impurity atoms implanted into a semiconductor substrate by ion implantation or plasma doping. However, the crystallization technique using laser has problems such as occurrence of a seam, and further, extremely expensive equipment is necessary.
Accordingly, a technique of performing heat treatment without a seam inexpensively by generating long thermal plasma and performing scanning only in one direction has been examined (for example, refer to JP-A-2013-120633 (Patent Document 1), JP-A-2013-120684 (Patent Document 2) and JP-A-2013-120685 (Patent Document 3) as well as Non-patent document 1 below).    [Non-Patent Document 1] T. Okumura and H. Kawaura, Jpn. J. Appl. Phys. 52 (2013) 05EE01